Recently, capacity of a battery built in a portable electronic device such as a tablet, smartphone, etc., has been increased. Because of this, the portable electronic device can continuously work for a long time while the time to fully charge the battery is long. To solve this inconvenience, application of not only a standard charging system in this technical industry, but also an own charging system of a manufacturer manufacturing the portable electronic devices (for example, a charging system using a larger voltage than the standard charging system of this technical industry) is increased.
The time to fully charge the battery can be reduced by applying the manufacturer's own charging system, as mentioned above. By applying the manufacturer's own charging system, however, another inconvenience arises that charging cannot be executed in the standard charging system in this technical industry or the charging time becomes very long in the standard charging system in this technical industry.
Thus, implement of new technology of solving another inconvenience is required.